feat(config): add validated persistent state

design/log.md

@@ -26,3 +26,10 @@ description: Chronological record of significant Trigger Spawn design decisions.
 - Added the Java 17 Gradle project targeting Spigot API 26.2, with JUnit 5 verification and versioned resource processing.
 - Added Gitea CI and semantic-release workflows modeled on `spigot-event-producer`.
 - Documented local builds, public releases, and the required `RELEASE_TOKEN` repository secret.
+
+## 2026-08-08 — Configuration and persistence
+
+- Added validated, independently configurable real-time cooldown tiers with documented defaults.
+- Added atomic YAML persistence for UUID-based player access state and per-world spawn settings.
+- Invalid persisted access values fail closed, while invalid required configuration disables the plugin rather than allowing partial startup.
+- Added friendly duration formatting and the administrative permission declaration.

design/user-stories/us-006-configure-plugin-behavior.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-006: Configure plugin behavior"
 description: Let operators tune cooldown tiers and run the plugin with clear validation, messages, permissions, and durable state.
-status: backlog
+status: done
 ---
 
 # US-006: Configure plugin behavior
@@ -11,17 +11,17 @@ As a **server operator**, I want safe configuration and durable state so that Tr
 
 ## Acceptance criteria
 
-- [ ] The one-kill cooldown is independently configurable and defaults to 28,800 seconds.
-- [ ] The two-kill cooldown is independently configurable and defaults to 14,400 seconds.
-- [ ] The three-kill cooldown is independently configurable and defaults to 3,600 seconds.
-- [ ] Configured cooldowns must be positive and representable safely by the plugin.
-- [ ] Invalid required configuration prevents partial initialization and produces a clear server log message.
-- [ ] Player-facing messages use clear built-in wording, readable colors, and friendly duration formatting.
-- [ ] Ordinary players do not require a plugin permission node to execute `/spawn`; eligibility is controlled by progression, grants, cooldowns, and bans.
-- [ ] Administrative commands require `triggerspawn.admin`.
-- [ ] Server operators receive `triggerspawn.admin` by default.
-- [ ] Boss progress, grants, bans, cooldown timestamps, latest known names, and per-world spawn settings persist across clean restarts.
-- [ ] Persisted data is handled defensively so corrupt or invalid records do not silently grant access.
+- [x] The one-kill cooldown is independently configurable and defaults to 28,800 seconds.
+- [x] The two-kill cooldown is independently configurable and defaults to 14,400 seconds.
+- [x] The three-kill cooldown is independently configurable and defaults to 3,600 seconds.
+- [x] Configured cooldowns must be positive and representable safely by the plugin.
+- [x] Invalid required configuration prevents partial initialization and produces a clear server log message.
+- [x] Player-facing messages use clear built-in wording, readable colors, and friendly duration formatting.
+- [x] Ordinary players do not require a plugin permission node to execute `/spawn`; eligibility is controlled by progression, grants, cooldowns, and bans.
+- [x] Administrative commands require `triggerspawn.admin`.
+- [x] Server operators receive `triggerspawn.admin` by default.
+- [x] Boss progress, grants, bans, cooldown timestamps, latest known names, and per-world spawn settings persist across clean restarts.
+- [x] Persisted data is handled defensively so corrupt or invalid records do not silently grant access.
 
 ## Related